test/bpf_load_tp_prog.c

/*
 * Copyright (C) 2018 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <linux/bpf.h>
#include <stdbool.h>
#include <stdint.h>
#include <bpf_helpers.h>

struct bpf_map_def SEC("maps") cpu_pid = {
        .type = BPF_MAP_TYPE_ARRAY,
        .key_size = sizeof(int),
        .value_size = sizeof(uint32_t),
        /* Assume max of 1024 CPUs */
        .max_entries = 1024,
};

struct switch_args {
    unsigned long long ignore;
    char prev_comm[16];
    int prev_pid;
    int prev_prio;
    long long prev_state;
    char next_comm[16];
    int next_pid;
    int next_prio;
};

SEC("tracepoint/sched/sched_switch")
int tp_sched_switch(struct switch_args* args) {
    int key;
    uint32_t val;

    key = bpf_get_smp_processor_id();
    val = args->next_pid;

    bpf_map_update_elem(&cpu_pid, &key, &val, BPF_ANY);
    return 0;
}

char _license[] SEC("license") = "GPL";